In situ XANES study of methanol decomposition and partial oxidation to syn-gas over supported Pt catalyst on SrTiO3 nanocubes

• Published in: Catalysis today 2014-11, Vol.237, p.71-79
• Main Authors: Wang, Hui, Lu, Junling, Marshall, Christopher L., Elam, Jeffrey W., Miller, Jeffrey T., Liu, HongBo, Enterkin, James A., Kennedy, Robert M., Stair, Peter C., Poeppelmeier, Kenneth R., Marks, Laurence D.
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Decomposition; Exact sciences and technology; General and physical chemistry; In situ XANES; Methanol; Partial oxidation; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Platinum nanoparticle; SrTiO3 nanocuboid; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2014.02.008

•In situ XANES is used to study methanol decomposition and partial oxidation on a supported Pt catalyst.•The catalyst is made by ALD of Pt on a single crystal of SrTiO3 nanocube with Pt (111) nanoparticles on the surface.•The as-received catalyst and the reduced or oxidized catalyst all have activity but show different selectivity for H2, CO and CO2.•In situ XANES observed CO on Pt the only surface adsorption species during the reactions.•The study confirms that the mechanism only includes the breakage of C–H and O–H bonds. A catalyst of Pt nanoparticles was prepared by atomic layer deposition on SrTiO3 nanocuboids and tested for methanol decomposition and partial oxidation. The catalyst had uniform nanoparticle size of 1.58±0.37nm and a Pt (111) surface. In situ X-ray absorption near-edge spectroscopy (XANES) measured in a temperature-programmed reduction showed that the Pt particles were easily reduced. However, the as-received catalyst, a reduced catalyst, and an oxidized catalyst all had catalytic activity, differing slightly in methanol conversion and product selectivity. In situ XANES also revealed that CO adsorbed on the Pt sites was the only observed surface species during both methanol decomposition and partial oxidation. It seemed that the breakage of CH and OH bonds overwhelmingly occurred once methanol was adsorbed, forming H2 and adsorbed CO. The latter was then released from the catalyst surface or was oxidized to CO2 when O2 was present.